TW202417930A - Near-eye display device - Google Patents

Abstract

Embodiments of the present application relate to the field of display technology and provide a near-eye display device. The near-eye display device includes an image source for emitting image light; a focusing assembly for changing a focal length of the image light; a coupling-in structure located between the image source and the focusing assembly for coupling the image light into the focusing assembly; an optical waveguide located on a light exit side of the focusing assembly; and a coupling-out structure located on a light exit area of the optical waveguide. The image light propagates in the optical waveguide after passing through the focusing assembly, and is coupled out of the optical waveguide from the coupling-out structure.

Description

Near-Eye Display

The present application relates to the field of display technology, and more specifically, to a near-eye display device.

Conventional near-eye display devices based on augmented reality (AR) technology have the problem of easily tiring the user's eyes and even causing dizziness.

The present application embodiment provides a near-eye display device. The near-eye display device includes: An image source for emitting image light; A focusing assembly for changing the focal length of the image light; A coupling structure, located between the image source and the focusing assembly, for coupling the image light into the focusing assembly; An optical waveguide, located on the light-emitting side of the focusing assembly; and An outcoupling structure, located in the light-emitting area of the optical waveguide; Wherein, the image light propagates in the optical waveguide after passing through the focusing assembly and is coupled out of the optical waveguide from the outcoupling structure.

Since the above-mentioned near-eye display device can change the focal length of the image light emitted by the image source by setting the focusing assembly on the optical path of the image light emitted by the image source, the user can adjust the distance from the virtual image formed by the image source to the human eye according to the needs, so that the virtual image seen by the human eye is variable in distance, rather than always in a fixed focus state, so that the ciliary muscle of the human eye can move accordingly, thereby relieving the fatigue of the human eye, avoiding the occurrence of dizziness, and achieving the purpose of relaxation. In addition, since the above-mentioned near-eye display device can change the focal length of the image light by the focusing assembly, users with different vision can directly wear the near-eye display device without having to wear myopia glasses first and then wear the near-eye display device, which solves the problem of inconvenience in wearing for myopic people and improves the wearing comfort.

Augmented Reality (AR) technology refers to a technology that uses the position and angle of the image source (also known as an optical machine or projector) and image analysis technology to enable the virtual scene on the screen to combine and interact with the real scene in the real world.

The following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

FIG1 is a schematic diagram of the structure of a near-eye display device 100 of an embodiment of the present application. As shown in FIG1 , the near-eye display device 100 is configured in the form of glasses (such as AR glasses). In other embodiments, the near-eye display device 100 may also be configured in the form of a helmet or goggles, which is not limited here.

Specifically, the near-eye display device 100 includes a lens frame 10, lens legs 20 connected to both sides of the lens frame 10, two lenses 30 disposed on the lens frame 10, and a focusing assembly 60 disposed on the lens frame 10. In the embodiment shown in FIG. 1 , both lenses 30 are optical waveguides 70.

Fig. 2 is a schematic diagram of the optical path of the near-eye display device 100 in Fig. 1. Fig. 2 is illustrated by taking the lens 30 corresponding to the right eye E of a person as an example. The lens 30 corresponding to the left eye of the near-eye display device 100 is symmetrically arranged with the lens 30 corresponding to the right eye E of a person in Fig. 2 and has the same structure.

As shown in FIG. 2 , the near-eye display device 100 further includes an image source 40 , an in-coupling structure 50 , and an out-coupling structure 80 .

Specifically, the image source 40 is used to emit the image light L1. The image source 40 can be disposed at the temple 20 shown in FIG. 1 . When the two lenses 30 of the near-eye display device 100 corresponding to the eyes of a person are both used to realize AR display, the number of image sources 40 can be two, and the two image sources 40 are respectively disposed at the two temples 20. Alternatively, the two image sources 40 are disposed at the positions of the frame 10 corresponding to the bridge of the nose. Since the image source 40 protrudes from the frame 10 when it is disposed at the position corresponding to the bridge of the nose, which is not conducive to the beauty of the AR glasses, the image source 40 is preferably disposed at the temple 20.

When the user wears the near-eye display device 100, the two lenses 30 correspond to the left eye and the right eye of the user respectively. The two image sources 40 located at the temples 20 respectively emit light with image information to provide virtual images to the two lenses 30 (or the two optical waveguides 70) respectively.

Specifically, the two lenses 30 (or the two optical waveguides 70) are transparent and can directly transmit light from the real world, so that the user can clearly see the real image in the real world through the two lenses 30. When the user wears the near-eye display device 100, the near-eye display device 100 can superimpose the virtual image with the real world, allowing the user to see an image that is a combination of the real image and the virtual image, achieving a sensory experience beyond reality.

For example, the near-eye display device 100 allows the user to experience virtual shopping. When the user wears the near-eye display device 100, the two lenses 30 transmit the image of the real world to the user's eyes, for example, the real world is a store. At this time, the user sees a real image of a store. In addition, the image source 40 can provide a virtual image to the optical waveguide 70, for example, the virtual image is the relevant information of the product (for example, the expiration date, origin, ingredients, etc. of the product). At this time, the optical waveguide 70 transmits the virtual image provided by the image source 40 to the user, and the image seen by the user is the relevant information of the virtual product in a real store.

In one embodiment, the type of the image source 40 is any one of an organic light-emitting diode (OLED) display, a micro light-emitting diode (Micro LED) display, a liquid crystal display (LCD), a liquid crystal on silicon (LCoS) display, a digital micro-mirror device (DMD) and a laser beam scanner (LBS). The light emitted by the image source 40 can be visible light, which can be a single wavelength light or include multiple wavelength bands of light (for example, red light, blue light and green light).

The coupling structure 50 is located between the image source 40 and the focusing assembly 60. The coupling structure 50 is used to couple the image light L1 emitted by the image source 40 into the focusing assembly 60. The optical waveguide 70 is located on the light-emitting side of the focusing assembly 60. The coupling structure 50 is, for example, a coupling grating. The coupling grating can diffract the image light L1 incident thereon and allow the diffracted light to enter the focusing assembly 60.

The coupling-out structure 80 is located in the light exiting area (also called the coupling-out area) of the optical waveguide 70 and is used to couple out the image light L1 in the optical waveguide 70. The coupling-out structure 80 is, for example, a coupling-out grating. After the image light L1 propagating in the optical waveguide 70 is diffracted by the coupling-out grating, the light that does not meet the total reflection condition of the optical waveguide 70 is coupled out of the optical waveguide 70 and enters the human eye to be perceived. In this process, part of the stray light L2 is coupled out in a direction away from the human eye.

The optical waveguide 70 is located on the light-emitting side of the focusing assembly 60. The focusing assembly 60 is used to change the focal length of the image light L1. Please refer to Figures 1 and 3 in combination. The focusing assembly 60 includes a housing 61 and a knob 65 disposed on the housing 61. The housing 61 is disposed on the lens frame 10 to avoid blocking the user's line of sight of observing the real world through the lens 30. The housing 61 can be disposed inside the lens frame 10 or on the surface of the lens frame 10, and the knob 65 can be disposed on the outer surface of the housing 61 and protrude from the side of the lens frame 10 for easy operation by the user.

As shown in FIG3 , the focusing assembly 60 further includes a first light guiding element 62, a second light guiding element 64 and a lens group 63. The second light guiding element 64 is spaced apart from the first light guiding element 62. The lens group 63 is located between the first light guiding element 62 and the second light guiding element 64. The first light guiding element 62, the second light guiding element 64 and the lens group 63 are all accommodated in a housing 61. The housing 61 is provided with a light inlet 611 and a light outlet 612. The image light L1 emitted from the coupling-in structure 50 is incident on the first light guiding element 62 through the light entrance hole 611, and the image light L1 coupled into the self-coupling structure 50 is sequentially coupled into the optical waveguide 70 through the light exit hole 612 after passing through the first light guiding element 62, the lens set 63 and the second light guiding element 64. The image light L1 is totally reflected and propagated in the optical waveguide 70, and is coupled out to the human eye at the coupling-out structure 80.

In the embodiment shown in FIG3 , the first light guiding element 62 and the second light guiding element 64 are both turning prisms. The first light guiding element 62 is used to guide the light coupled from the coupling structure 50 to the lens assembly 63. The second light guiding element 64 is used to guide the light passing through the lens assembly 63 to the light exit hole 612, and couple the light into the optical waveguide 70 at a specific incident angle.

It is understandable that in other embodiments, the first light guiding element 62 and the second light guiding element 64 are not limited to the folding prism. For example, the first light guiding element 62 and the second light guiding element 64 can also be a reflector, respectively. Alternatively, one of the first light guiding element 62 and the second light guiding element 64 is a reflector, and the other is a folding prism.

In one embodiment, the refractive index of the light guide 70 is 1.4 to 1.6 (such as transparent glass). To improve the color shift phenomenon, the turning prism is made of a material with a low refractive index, or in other words, the turning prism is made of a material with a refractive index close to that of the light guide 70. Specifically, the refractive index of the turning prism is 1.4 to 1.6, and the material of the turning prism is, for example, polymethyl methacrylate (PMMA), but is not limited thereto.

In addition, the near-eye display device 100 may further include a turning grating (not shown) located on the optical waveguide 70 to achieve lateral pupil dilation and longitudinal pupil dilation, thereby increasing the field of view and improving the user experience.

In the embodiment shown in FIG. 3 , the number of lenses in the lens set 63 is three, and each lens is a convex lens. Defining the direction from the first light guiding element 62 to the second light guiding element 64, the three lenses are the first lens 631, the second lens 632, and the third lens 633. The position of at least one of the three lenses can be adjusted by the user through the knob 65, so as to change the focal length before the image light L1 enters the optical waveguide 70. In particular, for users with different vision, the position of the position-adjustable lens in the lens set 63 can be adjusted by the knob 65 to achieve the need for zooming, improve wearing comfort and enhance viewing experience.

In other embodiments, the number of lenses in the lens group 63 is not limited to three, for example, one, two, or more than three. The type of lenses in the lens group 63 is not limited to convex lenses, for example, each lens can also be one of a concave lens and a concave-convex lens. In addition, regardless of whether the number of lenses in the lens group 63 is one or more, the position of at least one lens in the lens group 63 is adjustable to change the focal length of the image light L1.

As shown in FIG4A and FIG4B , the number of lenses in the lens group 63 is three, wherein the first lens 631 and the third lens 633 are convex lenses, and the second lens 632 is a concave lens. In the embodiment shown in FIG4A and FIG4B , the second lens 632 is a position-adjustable lens. As shown in FIG4A and FIG4B , the first lens 631 and the third lens 633 are fixed, that is, the distance D between the first lens 631 and the third lens 633 is a fixed value. The second lens 632 can translate back and forth along the optical axis X between the first lens 631 and the third lens 633 to change the convergence degree of the image light L1, thereby changing the distance from the virtual image formed by the image light L1 through the optical waveguide 70 to the human eye, thereby improving the wearing comfort. Especially for users with different vision, the user can adjust the focal length of the image light L1 through the focusing assembly 60 according to the clarity of the virtual image in front of the eyes, which is conducive to improving the viewing experience. In addition, in addition to adjusting the focal length, the focusing assembly 60 can also magnify and reduce the real image.

In one embodiment, the focusing assembly 60 further includes a position adjustment structure (not shown). The position adjustment structure is connected to the position-adjustable lens, and the position adjustment structure is used to drive the position-adjustable lens to move. The position adjustment structure, for example, includes a motor (not shown) connected to the position-adjustable lens, and the motor is used to drive the position-adjustable lens to translate.

Specifically, the position adjustment structure also includes a transmission mechanism (not shown) and a control unit (not shown). The motor is connected to the position-adjustable lens via the transmission mechanism. The control unit includes a signal input terminal (not shown) and a signal output terminal (not shown). The knob 65 is connected to the signal input terminal of the control unit. The motor is connected to the signal output terminal of the control unit. The user can give the control unit a control signal via the knob 65, and the control unit outputs a signal to the motor to drive the motor to rotate. The motor drives the transmission mechanism to translate the zoomable lens, thereby realizing the zoom function.

The transmission mechanism includes, for example, a driving gear (not shown) connected to the motor, a driven gear (not shown) meshed with the driving gear, a threaded sleeve (not shown) coinciding with the axis of the driven gear, and a screw (not shown) threadedly matched with the threaded sleeve. The rotation of the motor drives the driving gear to rotate, the driven gear rotates with the rotation of the driving gear, and the threaded sleeve rotates accordingly. The screw and the threaded sleeve are driven by the threaded match to move the position-adjustable lens in the lens group 63 connected thereto along the optical axis X direction, thereby achieving the purpose of adjusting the focal length of the near-eye display device 100. In other embodiments, the position adjustment structure is not limited to focusing by the cooperation of a gear pair and a thread pair, as long as the position adjustment structure can realize the movement of the lens.

In one embodiment, the number of lenses in the lens group 63 is one, and the lens is a meta lens (also called a super lens, meta lens). When the lens is a meta lens, it is possible to avoid the occurrence of dispersion of the image light L1 passing through the lens group 63. When the lens is a meta lens, the position-adjustable lens in the lens group 63 is a meta lens.

Specifically, superlenses are flat (planar) and ultra-thin, so they do not produce chromatic aberration. Superlenses are "achromatic" lenses because all wavelengths of light pass through them almost simultaneously. Unlike glass or other traditional materials with fixed dispersion, the advantages of superlenses also include tunable dispersion (the ability to control how light colors are dispersed). And because superlenses do not need to have the same curvature as refractive lenses, they are easier to process and can even be grown directly on a substrate using semiconductor process technology.

FIG5 is a schematic diagram of the imaging principle of a super lens in another embodiment of the present application. As shown in FIG5 , a super lens 634 includes a carrier 6341 and a plurality of micro-nano structures 6342 located on the carrier 6341. The micro-nano structures 6342 are nanorods. By adjusting the length, width, height, rotation angle and distribution regularity of the micro-nano structures 6342 on the carrier 6341, the amplitude, phase, polarization and other characteristics of the light incident on the super lens 634 can be adjusted, so that the light incident on the super lens 634 (for example, the image light L1 including red light, green light and blue light) is focused at a specific position.

Specifically, according to the optical path requirements, the focusing position of light of different wavelengths can be calculated by analogy with optical software, and then the length, width, height, rotation angle and distribution law of the micro-nano structure 6342 on the carrier 6341 can be modified to obtain the required structural parameters of the super lens, so that the three primary colors of light (i.e., red light, green light and blue light) are focused on the same point. Then, a semiconductor process is used, such as coating and etching the required pattern, to grow a plurality of micro-nano structures 6342 on the carrier 6341 to obtain the required super lens. In one embodiment, the micro-nano structure 6342 is a titanium dioxide nanorod, and its height is approximately 600 nanometers, but not limited to this. The material of the carrier 6341 is transparent glass, transparent plastic or other low refractive index materials.

In summary, the near-eye display device of the embodiment of the present application, because the adjustment component can change the focal length of the image light emitted by the image source, allows the user to adjust the distance from the virtual image formed by the image source to the human eye as needed, so that the virtual image seen by the human eye is variable in distance rather than always in a fixed focus state, so that the ciliary muscle of the human eye can move accordingly, thereby relieving the fatigue of the human eye, avoiding the occurrence of dizziness, and achieving the purpose of relaxation.

In addition, since the above-mentioned near-eye display device can change the focal length of the image light through the focusing component, users with different vision can directly wear the near-eye display device without having to wear myopia glasses first and then wear the near-eye display device, which solves the problem of inconvenience in wearing for myopic people and improves the wearing comfort.

Moreover, in the embodiment of the present application, the focusing assembly of the near-eye display device is located at the lens frame to achieve focusing of the virtual image, and will not block the view of the real world (real image) directly in front of the eyes when in use.

The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

100: Near-eye display device 10: Lens frame 20: Lens leg 30: Lens 40: Image source 50: Coupling structure 60: Focusing assembly 61: Housing 611: Light entrance hole 612: Light exit hole 62: First light guiding element 63: Lens assembly 631: First lens 632: Second lens 633: Third lens 634: Super lens 6341: Carrier 6342: Micro-nano structure 64: Second light guiding element 65: Knob 70: Optical waveguide 80: Coupling structure L1: Image light L2: Stray light E: Right eye D: Distance X: Optical axis

FIG1 is a schematic diagram of the structure of a near-eye display device according to an embodiment of the present application.

FIG. 2 is a schematic diagram of the optical path of the near-eye display device in FIG. 1 .

FIG. 3 is a schematic structural diagram of the focusing assembly in FIG. 2 .

FIG. 4A and FIG. 4B are schematic diagrams of the optical path of a position-adjustable lens at different positions in an embodiment of the present application.

FIG5 is a schematic diagram of the imaging principle of a superlens in another embodiment of the present application.

100:Near-eye display device

30: Lens

40: Image source

50: Coupling structure

60: Focusing assembly

70: Optical waveguide

80: coupling out structure

L1: Image light

L2: stray light

E: Right eye

Claims (10)

A near-eye display device comprises: an image source for emitting image light; a focusing assembly for changing the focal length of the image light; an incoupling structure located between the image source and the focusing assembly and used to couple the image light into the focusing assembly; an optical waveguide located on the light-emitting side of the focusing assembly; and an outcoupling structure located in the light-emitting region of the optical waveguide; wherein the image light propagates in the optical waveguide after passing through the focusing assembly and is coupled out of the optical waveguide from the outcoupling structure. A near-eye display device as described in claim 1, wherein the focusing assembly comprises: a first light guiding element; a second light guiding element, spaced apart from the first light guiding element; and a lens group, located between the first light guiding element and the second light guiding element; wherein the lens group comprises at least one position-adjustable lens, and the image light emitted from the coupling structure is coupled into the optical waveguide after passing through the first light guiding element, the lens group and the second light guiding element in sequence. A near-eye display device as described in claim 2, wherein the number of lenses in the lens group is plural, and each of the lenses is one of a convex lens, a concave lens, and a concave-convex lens. A near-eye display device as described in claim 2, wherein the number of lenses in the lens group is one, and the lens is a super lens. A near-eye display device as described in claim 2, wherein the first light guiding element is one of a reflective mirror and a turning prism, and the second light guiding element is one of a reflective mirror and a turning prism. A near-eye display device as described in claim 5, wherein the first light guiding element and the second light guiding element are both turning prisms, the refractive index of the optical waveguide is 1.4 to 1.6, and the refractive index of the turning prism is 1.4 to 1.6. The near-eye display device as described in claim 2, wherein the focusing assembly further includes a housing, and the first light guiding element, the second light guiding element and the lens group are all accommodated in the housing; The housing is provided with a light entrance hole and a light exit hole, and the image light emitted from the coupling structure is incident on the first light guiding element through the light entrance hole, and the image light emitted from the second light guiding element is coupled into the optical waveguide after passing through the light exit hole. A near-eye display device as described in any one of claims 2 to 7, wherein the focusing assembly further includes a position adjustment structure, the position adjustment structure is connected to the position-adjustable lens, and the position adjustment structure is used to drive the position-adjustable lens to move. A near-eye display device as described in claim 8, wherein the position adjustment structure includes a motor, the motor is connected to the position-adjustable lens, and the motor is used to drive the position-adjustable lens to translate. A near-eye display device as described in claim 9, wherein the focusing assembly further includes a transmission mechanism, a knob and a control unit; the motor is connected to the position-adjustable lens via the transmission mechanism; the knob is connected to a signal input terminal of the control unit; and the motor is connected to a signal output terminal of the control unit.

Images